From Michael Burgess at Stanley Street:

The feeling here is that it was an abdominal issue, or possibly hip flexor. It probably happened in the second to last game of the first set, as Osaka was holding herself back on serve in the 5-4 game, even though she won it.

"I know how good she is, and we've seen the entire week how good she is. I really felt today she was picking up an even higher level," Tauson told Sky Sport of Osaka. 

"I'm super sad about the way it ended, but I feel I was getting a bit more into the match in the end. I don't know if that was because she had some pain in her back, but me personally, I've been dealing with back issues for a long, long time so I know how difficult it is and you really have to take care of yourself. 

"I'm not happy that she did that, but I think shes right to put herself first, always."

Tauson is draped in a korowai - as has become tradition for ASB Classic winners - commissioned from Ngāti Whātua Ōrākei and receives the winner's cup. 

Tauson and Osaka stand side by side for a photo op - and neither look particularly happy.

A win is a win though. Tauson played quality tennis all week, setting the tone early with an impressive straight sets win over Italian Lucrezia Stefanini. 

She also beat Sofia Kenin, Madison Keys and Robin Montgomery  (all USA) en route to the final.  

Clara Tauson on her title in Auckland:

"I'm really sorry about this final. Naomi was playing some great tennis today so that's the worst final I've ever played for me emotionally.

"I can't feel happy and am just sad about what happened today, but of course when I process this I'm going to be super happy about my week. I played a lot of tennis on this court. 

"I'm happy that I won, but not really"

"I just want to thank everyone for welcoming me to such a beautiful city," Naomi Osaka said in her post-game interview. 

"I've really enjoyed playing here. I'm sorry for how today ended but I hope that you enjoyed the tennis that we did play. I'm just really grateful to be here."

She was not asked about the nature of the injury. 

From Michael Burgess at Stanley Street

The crowd is still in a bit of shock here. A lot hadn't heard the initial announcement from the umpire and thought Osaka was just leaving for a break at the end of the first set. Reality has set in now. It's extremely sad for Osaka, who was superb throughout the opening set, with her power and precision from the baseline.

Both players are back out of the court for the presentation, so we might get a bit more information. 

Has to be a very strange feeling for Tauson too. She played some good tennis in the set and did well to fight back to 5-4 after going 5-1 down, but how does a professional athlete react to claiming a title when the scoreboard shows they're behind?